Safety-plug.



J. J. BARRY &. F. L. STREET.

SAFETY PLUG.

APPLICATION FILED NOV. 25, 1912.

1,096,346. Patented May 12, 1914.

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M Attorneys.

UNITED STA'EgS PA TENT @FFKCE.

JOHN J'. BARRY, OF WICHITA, AND FRANCIS L. STREET, NEODESHA, KANSAS.

SAFETY-PLUG.

Application filed November 25, 1912.

To 01 Z whom it may concern:

Be it known that we, JOHN J. BARRY and l nnNois L. Srnnn'r, citizens of the United States, residing respectively, at W'ichita and Neodesha, in the counties of Sedgwick and \Vilson, State of Kansas, have invented a new and useful Safety-Plug, of which the following is a specification.

This invention relates to safety systems for steam boilers and more particularly to that class of systems in which a fusible plug is positioned adjacent the crown sheet of the the box, the melting of which plug opens a pipe through which the water and steam pass to extinguish the fire.

The object is to provide means for extinguishing the fire upon the fusing of the safety plug. a

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, can be made within the scope of what is claimed, without departing from the spirit of the invention.

Tn the drawings accompanying this specilication and forming a part thereof the preferable form of our invention is illustrated, in which Figure 1 is a sectional view in elevation of the safety device including the fusible plug. Fig. 2 is a cross sectional plan view taken on the line .[l A of Fig. 1. Fig. 3 is a plan cross sectional view taken on the line BB of F 1. Fig. 4 is a cross sectional view in elevation of the improved valve which is used. in connection with the safety device, and Fig. 5 is a cross sectional view taken on the line CG of Fig.4. Fig. 6 is a sectional view of a boiler and fire box with our improved device.

Referring to the drawings in which similar reference numerals designate corresponding parts throughout the several views, 1 represents the crown sheet of the fire box and 2 the boiler shell, the upwardly extending portion of the shell 3 forming a portion of the side wall of the steam dome. Threadedly engaging an opening in the crown sheet Specification of Letters Patent.

Patented May 12, 191-1.

Serial No. 733,499.

1 the casing generally designated by the letter I), this casing being provided with a projecting hexagonal shoulder 4- at the upper terminal of a threaded portion 5. This casing D is provided with a central extending threaded portion 6 and an opening 7 thereabove. Extending upwardly through the casing and communicating with the opening 7 is the opening 8 into which is secured the lower terminal of the pipe 9. Communicating with the opening 8 is a passage 10, which passage communicates with the pipe 11 extending therein.

A. fusible plug 11 is positioned within the opening 7 and rests upon the upper surface of a threaded plug l 2, which threaded plug 12 engages and lies within the opening (3. In order that the plug 12 may be inserted within or withdrawn from said opening, it is provided upon its lower surface with the slot 13 which may be engaged by a screw driver or other suitable means for rotating the said plug. A passage 14 communicates with the upper portion of the opening 7, the said passage 1 however, lying below the upper edge of the fusible plug 11 and is therefore effectually sealed thereby. Communicating with the passage 14 is a pipe 15. A passage 16 communicates with the lower portion of the opening 7 at a point above the lower terminal of the fusible plug 11 and is therefore also effectually sealed thereby. The passage 16 extends vertically upward through the upper portion of the casing D and communicates with the pipe 17. The pipe 9 communicates with the steam dome and thereby exerts a continuous pressure upon the top of the fusible plug 11. The opening communicating with the pipe 11 is sealed by means of the valve 18. as illustrated in Fig. 2. The purpose of this opening with its valve 18, is that by opening the valve 18, the steam is blown down through the passage 9 across the top of the fusible plug 11 and out through the valve 18, thus insuring that the fusible plug will remain in a clean condition. The passage 16 and its pipe 17 communicating therewith is open to the atmosphere so that when the fusible plug is melted, the pressure of the steam upon the top thereof, in the pipe 9 will force the melted metal out through and into the passage 1.6 which will establish communication between the pipe 9 and the passage 14 and pipe 15. Pipe 15 leads to various points in the fire box and the steam going through the pipe 15 is adapted to extinguish the fire and reduce the abnormal conditions which melted the fusible plug 11'.

I order that the various pipes 9, 11, 15 and 17 may pass through the boiler shell 2, the plate illustrated in section in Fig. 2 is provided, the various pipes leading to suitable passages through this plate, which is generally designated by the letter E and is provided with a ground joint to the boiler shell as at 19. The plate is held in position with the boiler shell and within the joint 19 by means of a suitable bolt 20. The pipe 9 communicates with a passage 21 in the plate or casting E, the other end of which passage communicates with the pipe 22, which pipe 22 enters the boiler shell and terminates withinthe steam dome to thereby supply steam pressure upon the top of the fusible plug 11 as hereinbefore described. The passage 17 communicates with a passage 23 in the plate which is connected to a pipe 24, the end of which is open and communicates with :the atmosphere, the purpose being to allow the fusible plug 11 when in a melted condition to be forced out through the open ing in the pipe 24. The pipe 15 communic ates with a passage 25, which passage is connected to the pipe 26, this pipe 26 being the pipe which leads to the boiler fire box and through which the steam flows in order to extinguish the fire. The pipe 11 connected to the opening 10 is connected to the passage 27 in the plate E, the outer end of which passage is provided with the hereinbefore mentioned valve 18.

In order that water may be blown in upon the fire as well as steam upon the fusing of the plug-11, what may be termed as a release valve "is connected to the pipe 26 by the pipe 28. This release valve comprises a cylinder 29 in which is positioned a. piston head 30. The piston rod31 extends, upwardly and through the cylinder head 32, and has a handle 31 at the end thereof, whichcylinder head is provided with the usual: packing and packing nut, all of which is illustrated in detail in Fig. 1. A suitable outlet 33 is providedat the lower terminal of the cylinder and is. for the. purpose of acting as a drain for the water of condensation of the steam. The lower portion of the cylinder 29 is provided with the integral head 34, through which head extends the pistoirrod 31. Rigidly supported by the head 84- is the circular member 85 which is provided with the downwardly extending circular projection 86, which project-ion is threadedly engaged by means of the member 37 which constitutes the valve seat of the hereinsdescribed release valve. The lower portion of the member 37 is provided with the threaded portion 38 and the hexagonal shoulder 89 at the upper terminal thereof, the portion 38 being adapted to extend within and threadedly engage the boiler shell at a point located adjacent the bottom of the boiler so as to insure that the portion 38 will always lie below the water level in the boiler. The member 37 is provided with the axial opening 1 0 which is provided adjacent its lower terminal with a valve seat 41. An opening in the member 37 is suitablyengagcd by the pipe 4.2 communicating with the opening 40. A valve is located within this member 87 and is provided with the valve seat as adapted to act as a closure for the opening 410. The valve stem 1% is formed integral with the valve seat 13 and is substantially triangular in cross section for a short distance above which it merges into a round rod 45, the upper portion of which rod a5 is engaged by the lower flanged portion of the piston rod 31. Suitable packing and packing nutsare provided adjacent the portion 15 of the valve stem in order to render the joint between the valve stem and the wall tight. The pipe 28 communicates with an opening in the upper cylinder head 82 and is adapted to supply pressure to the piston head 30 when the fusible plug 11 has.

melted, there being a connection between the pipe 26 and the pipe 28. The pipe 42 which communicates with the opening 40 of the relief valve is connected to suit-able spraying apparatus in order to distribute the water which is to extinguish the fire, over the entire fire grate. When the. water in the boiler becomes abnormally low and below the crown sheet of the tire box, it is well known that there is extreme danger unless the fire be extinguished immediately. lVhen this condition is reached, the crown sheet will start to heat to an excessive temperature which will be communicated by reason of the plug 12 to the fusible plug 11, the top of which plug 11 is subjected at all times to boiler pressure by means of the pipes 9, 21 and 22, and as the passage 16 is open to the atmosphere through the pipe 17,. passage 23 and pipe 24-, the plug 11 when fused will be forced within the pipe 17 and therefrom, which will establish communication between the boiler and fire box through vthe passage means of the pipe 28 which pipe will; estab-.

lish a pressure above the piston 30 within the cylinder 29 and will force the pistonhead.

30 and cylinder head; 32 apart. The rod 31.

thereby being forced (.lownwardly will unseat the valve 43 from its seat l1, which will allow water from the boiler entering by the opening ll to flew up through the opening -il-0 between the walls thereof and the triangular valve stem 44: and out through the pipe 42 which as previously ex v lained, is connected to suitable spraying apparatus or other nozzles 26 for directing the water upon the fire in the fire box, to thereby extinguish the fire and prevent the crown sheet from being abnormally heated and prevent disastrous explosion by the failing of the crown sheet.

Having thus fully described the construction and operation of our improved safety system for steam boilers, what we claim to be new and original with us is z- 1. In a safety system for boilers, a casing threadedly engaging the fire box crown sheet, a circular lcad-in plate fitting-in the boiler shell, adapted to lead pipes through said boiler shell to said casing, a steam dis charge pipe connected through said plate with said casing, a fusible plug Within said casing and closing said discharge pipe, a steam supply pipe connected through said plate with said casing above said plug, a pipe connnunicating with the casing adjacent the lower portion of said fusible plug and leading to the atmosphere and adapted to act as a discharge pipe for said plug when in a fused condition, a blow-out opening adjacent the upper edge of said fusible plug, a valve controlling said blow-out opening, said steam discharge pipe communicating with the fire box.

2. In a safety system for boilers, the combination of a casing, a steam supply pipe leading thereto, a steam discharge pipe lead ing therefrom, a fusible plug disposed be tween said steam supply pipe and said steam discharge pipe and adapted to act as a closure for the latter, a pipe communicating with the atmosphere and with the said casing adjacent the lower portion of said fusible plug and adapted to act as a discharge pipe for said plug when in a fused condition, a piston operated water relief valve communicating with said steam discharge pipe from said casing and adapted to be actuated thereby, said water relief valve communicating with said boiler below the water level thereof, a pipe communicating with said water relief valve and the boiler fire box adapted to spray water therein when said water relief valve is open.

3. In a safety system for steam boilers, a casing supported by the fire box crown sheet, a lead-in plate fitting in the boiler shell adapted to lead pipes through said boiler shell to said casing, a steam discharge pipe connected through said plate with said casing, a fusible plug within said casing and closing said discharge pipe, a steam supply pipe connected through said plate with said casing, a pipe communicating with the said casing adjacent the lower portion of said fusible plug and leading to the atmosphere and adapted to act as a discharge pipe for said plug when in a fused condition, a blowout opening adjacent the upper edge of said fusible plug, a valve controlling said blow- .out opening, said steam discharge pipe communicating with a relief valve, said relief valve being pressure controlled and adapted to supply water to said lire box from said boiler upon the fusing of said plug.

4:. In a safety system for steam boilers, a casing threadedly engaging the fire box crown sheet, a circular lead-in plate fitting in the boiler shell adapted to lead pipes through said boiler shell to said casing, a steam discharge pipe connected. through said plate with said casing, a fusible plug within said casing and closing said discharge pipe, a steam supply pipe connected through said plate with said casing above said plug, a pipe communicating with the said casing adjacent the lower portion of said fusible plug and leading to the atmosphere and adapted to act as a discharge pipe for said plug when in a fused condition, a blow-out opening adjacent the upper edge of said fusible plug, a valve controlling said blow-out opening, said steam discharge pipe communicating with a relief valve, said relief valve providcd with a water supply inlet port therein, a water discharge pipe leading there from, a cylinder, a piston head and rod therein, said piston rod being provided at its lower extremity with a valve head, said valve head controlling said water discharge pipe leading therefrom, said water discharge pipe ommunicating with the boiler fire box, said steam discharge pipe from said casing to said relief 'alvo communicating with said relief valve cylinder adapted to supply pressure at the fusing of said plug to said cylinder and thereby open the water supply pipe.

5. In a safety system for steam boilers, a casing threadedly engaging the fire box crown sheet, a circular lead-in plate fitting in the boiler shell adapted to lead the pipes through said boiler shell to said casing, a steam discharge pipe connected through said. plate with said casing, a fusible plug within said casing and closing said discharge pipe, a steam supply pipe connected through said plate with said casing above said plug, a pipe communicating with said casing adjacent the lower portion of said fusible plug and leading to the atmosphere and adapted to act as a discharge pipe for said plug when in a fused condition, a blow-out opening adjacent the upper edge of said fusible plug, a valve controlling said blow-out opening,

said steam discharge .pipe communicating as our own, We have hereto affixed our-signe- With the said fire box and with a relief valve, tures in the presence of two Witnesses.

said relief valve being pressure controlled 7 JOHN J BARRY.

and adapted to supplywater to said fire box FRANCIS L. vSTREET.

from said boiler upon the :fusing of said WVitnesses:

plug. JAMES I. PIOKERING,

In testimony that We claim the foregoing HE RY WALKER. I

Copies-of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). G. i 

